Dental impression tray



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Patented Sept. 23, 1924.

FRANK C. RODGERS, 0F ST. LOUIS, MISSOURI.

DENTAL IMPRESSION TRAY.

.Application filed .Tune 16, 1920. Serial No. 389,384.

To all whom t may concern.'

Be it known that l, FRANK C. Bonares, a citizen of the United States, and residing at St. Louis, Missouri, have invented the new and useful Improvement in Dental Impression Trays, of which the following is a specification.

This invention relates to dental impression trays adapted for the purpose of taking impressions of the mouth to reproduce impressions of teeth, gums, palate and adjacent structures.

One of the objects of this invention is to provide an impression tray which is so shaped as to conform to the vault of the arch and the curvature assumed by the teeth and the gums so as to insure correct and accurate impressions.

Another object is to provide a dental impression tray which, while it is constructed to conform generally to the parts to be reproduced, has provisions for preventing the impression material from dropping` off of the tray into the mouth or throat, at the same time permitting` ready removal of the tray from the impression material and providing ample space for teeth that are out of alinement.

Another object is to provide a dental impression tray which is so shaped that it will not gouge into the gums or interfere with the muscle attachment at any point when the tray is adjusted in the mouth.

Another object is to provide a dental impression tray in which the front fiange or portion is so constructed as to force the impression material against the gum and under the lip so as to conform to protruding teeth and their gums.

Further objects will appear from the detail description taken in connection with the accompanying drawings, in which:

Figure l is a perspective View of a dental impression tray embodying this invention and more particularly of a tray for the upper jaw;

Figure 2 is a front elevation showing the impression material in place;

Figure 3 is a section on the line 3 3, Figure 2;

Figure l is a section on the ine 4*-4, Figure 3, but with the impression material removed;

Figure 5 is a perspective view of a tray, such as shown in Figure l, but with the loose forming element thereon;

Figure 6V is a View but with the forming and Figure 7 is a perspective view of the forming element.

Referring to the accompanying drawings, and more particularly to Figures l to l inclusive, the tray comprises a structure which may be formed of metal, such as aluminum, which may be shaped by stamping or by die-casting. The structure comprises labial flanges l merging into the front flange 2, while arranged centrally between the flanges is a palate portion 3, forming with the fianges, an arched trough. A suitable handle 4l may be formed on or attached to the body of the tray. While the trough is distally open, there is formed at its terminus a ridge 5 which is, however, very shallow and which runs transversely across the fianges l, the bottom of the trough and along the end of the palate portion.

The flanges l incline and curve distally so as to conform to the gums on the upper jaw while the palate portion 3 is so shaped that it conforms to the Vault of the arch, it having a gradual upward slope from the incisor teeth distally towards the soft palate. The bottom or base of the tray has a convex curvature distally so as to correspond to the curve of the teeth, which curve is designated as the curve of Spee in order to bring the impression material close to the back teeth. The space between the flange and the palate portion is concave laterally which is a distinct advantage in removing the impression tray from the impression material while in the mouth, also providing ample space for teeth that are out of alinement. The form of the slope given to the palate portion and the ridge 5males it possible to bring the impression material in close contact with and against the tissue but prevents it from dropping off the tray into the mouth or throat. In View of the fact, however, that the ridge 5 is shallow, the trough is really left open distally and while this ridge forms a p0st-dam for the impression material, it does not interfere with the molars but permits a close impression to be made.

The marginal edges of the flanges l and 2 are so shaped that the tray will not gouge into the gums nor interfere with the muscle attachment at any point when the tray is adjusted in the mouth. This slope corresimilar to Figure 5 element in position;

sponde to the relative contour of the gum from the anterior teeth towards the molars, having the highest point in the front with a gradual reduction to the distal end of the tray.

The front iiange 2 has a notch 6 which is adapted to receive and form a distinct rib 7 on the impression material 8. It is the practice to out a groov'e in the impression mate rial over the gum for the purpose of providing a leverage point for a tool in order to break the impression. material in order tosecure its removal from the mouth. The notch 6 is of such shape and size so as to provide asuiiiciently enlarged rib 7, in order to permit a deep groove 9` to be cut therein so as to provide for sufiicient leverage to permit breaking of the set impression on material so as to permit its removal from the mouth without requiring the cut to be suiliciently deep so as to possibly go through the impression and injure the gum.

It is sometimes necessary to take an iinpression of protruding` teeth that form a more or less horizontal angle to the front langeof the impression tray. In accordance with this invention, as illustrated in Figures, 6 and 7, a loose impression forming element 101s provided which is arranged to be placed on the front flange 2 of the tray but which is arranged to form a loose connection therewith by providing` a lug 11 spaced from this element. This element is placed on the front iiange 2 and centered in the notch 6, the lug 1lA taking over the flange and holding it loosely in position. The inside face of the element does not only merge into the inside face of the flange but also projects distally. Accordingly the element l0, when in place, really forms a continuation of the divided parts and forms therewith an overhang'ing flange.

lVhen it is desired to take an impression of the upper surface of, protruding tee-th and their gums, the element` l0 is placed on the tray as shown in Figures 5 and 6; accordingly the impression material will be forced upward and over the surfaces of the upper teeth and gums underneath the lip and under the lip so as to take an accurate impression.l Vhen, however, the tray is removed from the mouth, this loose piece becomes separated from the tray so as to permit ready removal of the tray from the impression ma-4 terial.

It is obvious that various changes may be made in the details of construction withont'departing from the spirit of this invention; it is therefore, to be understood that this invention is not to be limited to the specific details shown and described.

Having thus described the invention, what is claimed is: y

1. Adental impresion tray formed to provide a distally open arched trough having shallow post dams formed thereon and followinrr the transverse curvature of the trougli.

2. A dental impression tray formed to provide a palate portion and a surrounding trough having shallowr post dams formed thereon and following the transverse curvature of the trough and palate portion.

3. A dental impression tray embodying a palate portion and a surrounding trough, characterized by a shallow darn at the distal terminus of said palate portion and trough, and following the transverse curvature of the trough and palate portion.

4. A dental impression tray embod ing a palate portion formed to slope distal y and a surrounding trough, and a shallow post dam at the terminus of said palate portion and said trough and following the transverse curvature of the trough and Ypalate portion.

5. A dental impression tray embodying a palate portion and a surrounding trough, the bottom of which concaves distall in order to bring the impression material c ose to the back teeth.

6. A dental impression tray embodying a palate portion formed to slope distally and a surroumling trough, the bottom of which trough concaves distallv in order to bring the. impression material close to the back teeth.

'7. A dental impression tray embodying a palate portion and a surrounding trough. the bottom of which concaves laterally and distally in order to bring the. impression material close to the back teeth.

8. A dental impression tray embodying a palate portion and side flanges formedrto slope distally but oppositely and which bound a distally open trough.

9. A dental impression tray having a front flange provided with a deep and tapering notch adapted to reecive the impression material in order to provide a severing rib thereon. i

10. A dental impression tray having an overhanging front fiange portion adapted to force the impression material against the gum and under the lip.

l1. A dental impression tray having an overhanging front flange portion adapted to conform to protruding teeth and their gums.

1Q. A dental impression tray having a flange provided with a. loose impression material forming element.

13. A dental impression tray having a `front flange provided with an overhanging impression material forming element. i i

14. A dental impressiont-ray having a front {iange Aprovided with a notch, and a loose impression material forming element fitting said Harige. V

In testimony whereof I aix my signature this 28th day of April. 1920.

FRANK C. RODGERS. 

